Slippery Rock Gazette

Ben Cole

Cole Brothers

Stone Industry Consultant

Above: Scorpion CNC Sink and Seam Wheels are a brazed diamond product used for smoothing out the seams before joining two stone slabs together. The 50 grit wheel is designed to remove about 0.02˝ of stone.

Above: The Omni Cubed VCM Seam Setter offers manual, AC or battery vacuum operation to firmly pull seams together for perfect contact while adhesive cures.

Talk to most old-school fabricators and they will tell you that the proper place to put a seam, when possible, is in the sink line. However, this old belief does not take into account new technology that allows seams to be made almost invisible. To better educate yourself on where you should be placing seams, you need to understand why the sink line was the place of choice for so many years.  

My father, along with many of his colleagues, was a strong advocate of always placing the seam in the sink line. Going back ten years or more I would have agreed that the sink line was the best place to put a stone countertop seam, for multiple reasons. First, the sink line allows for the smallest seam possible as the sink bowl removes a large part of the seam and the faucet often helps to cover part of the back seam. Second, it is easier to deal with crowning issues or warped materials when you only have a small seam to manage and you are only dealing with the front and back of the seam. Third, it can be easier to color match the seam in a smaller area.  

But granite and stone seams had a bad reputation for many years, especially when compared to solid extruded products like Corian–which have no seam. Seams ten years or more ago tended to be wider (1/8˝) and more noticeable due to the large numbers of fine chips that ran along both edges of each piece.  These small chips were caused by the saw blade and it was standard practice to join two pieces that had just been cut with a bridge saw blade without any other prep work.  

Some customers even chose other products because of these unsightly seams, in such an expensive product.

Thankfully, new technologies over the past few years have really changed the dynamics and art of seam placement. There are two pieces of technology that revolutionized the stone seam and these are the Scorpion Seam Wheel (along with other similar seam chip removal devices) and seam clamps (like the Omni Cubed Seam Setter). Tools like the Scorpion Seam Wheel eliminate the unsightly chips left when a piece of stone is cut with a standard blade. Specialized seam tools also make both pieces a true ninety-degree angle for a perfect fit, with a tiny seam line.  

Often times in the past when a bridge saw blade was cutting a piece of granite, the blade would have a slight wiggle of a sixteenth of an inch or more due to the hardness of the stone.  This would cause the two pieces of stone to not join tightly and often left a wider and more unsightly seam.  Improvements in diamond and blade technology along with tools like the Scorpion Sink Wheel have helped to eliminate this issue. Pneumatic or powered seam clamps also were a brilliant invention that allows two pieces of stone to be held tightly together while the adhesive hardens. The pneumatic seam clamps also allow the operator to eliminate crowning and warping issues on main seams with the use of cams that put pressure down on areas of the seam that are sticking up higher than other areas.  

These relatively new inventions have drastically improved how tight and nearly invisible either a sink line seam or main seam can be made. Customers now often have to look to find the seam, where in times past, it would be painfully obvious where the seam was located. 

New technology has also challenged the old idea of the seam needing to be placed at the sink line. If you can now make a nearly invisible seam and you have eliminated most crowning and warping issues, then why put a seam in the area of the countertop that is used the most, and in a place that will be seen the most? Why not make more main seams away from the sink line?  

Now, don’t get me wrong. There are still times when putting the seam in the sink line makes sense. Color matching and grain matching the seam are two other important issues that fabricators ought to consider. Needless to say, the waste factor or how much of the slab is being used is also always part of the equation. But the idea that you should do everything in your power to put the seam in the sink line is certainly dated and no longer holds true in the age of nearly invisible seams.

And on a final note: it is always important to make sure your customers are aware of where the seams will be in their countertops and why they are being placed in that location. Educating and communicating about seam placement is a sure way to avoid headaches or misunderstandings with a homeowner.